Process of producing colored reversal images



g. l l i Patented Jan. 12, 1954 PROCESS OF PRODUCING COLORED REVERSAL IMAGES Andr Rott, Wilrijk-Antwerp, Belgium, assignor to Gevaert Photo-Producten N. V., Mortsel- Antwerp, Belgium, a company of Belgium N0 Drawing. Application August 8, 1947, Serial No. 767,662. In Germany August 2, 1941 Section 1, Public Law 690, August 8, 1946 Patent expires August 2, 1961 6 Claims.

This invention relates to the production of color images by means of silver halide diifused from an exposed light-sensitive silver halide emulsion layer into a layer, inert to light, which is-in contact with the layer first mentioned. The present invention is an improvement of the process and material described in my patent of the United States, No. 2,352,014, which relates to the production of photographic reversal images by the diffusion of the silver halide not affected by the light in an exposed silver halide layer into a receiving layer which is not sensitive to light, and reducing the diffused silver halide in the receiving layer. In the material'used in this process, the sensitive layer and the receiving layer may be mounted on two separate supports. After exposure, the sensitive layer was pressed upon the reception layer in presence of the substances capable of producing the positive reversal image, either by direct reaction with the diffused silver halide in the reception layer or by induced reaction or by catalytic reaction.

Instead of using separate supports for the sensitive layer and for the reception layer, both these-layers are preferably coated in superposition upon one and the same support. Substances of the kind referred to in my prior patent mentioned above as fogging agents, which are capable of accelerating the reduction of the silver halide not affected by the light and of forming crystallisation nuclei for silver halide may be admixed to the light-sensitive layer. If they are present ina receiving layer-containing an adequate'dyestuff, also color images can be obtained, this dye-'- stufi being then bleached out in proportion to v the silver of the reversal image in the reception layer,- and in this way, the color image is pro duced.

The reversal image may also be formed by color development. A first method consists in developing the exposed material in an ordinary developer, allowing the non-light-affected silver halide to diffuse into the reception layer, then developing the reversal image in an ordinary developer, rehalogenizing the reversal image and finally redeveloping the halide thus formed in a color developer. After removing the two silver images, a colored reversal image is left.

I'have found that both the diffusion and the color image formation may also be carried out in a single treatment. For this purpose, the material is washed after the first usual development in order to remove entirely the developer. Next it is treated in a color developer containing a silver salt solvent. The not-reduced silver salt diffuses into the receiving layer forming therein both a silver image and a dyestuff image by the action of the substances accelerating the reduction. To those skilled inthe art of color photography, it is obvious that the color couplers may be present in the color developer or in the receiving layer.

In case the coupler in the receiving layer is diffusion-fast, the silver salt solvent may be added to the primary developer. The diffusion of the non-reduced silver halide consequently takes place already in the first development phase, and in such a way that an image is formed in the emulsion layer and at the same time a reversal image in the receiving layer. After washing, the two silver images are re-halogenized and re-developed in a color developer; now a silver image is formed in the emulsion layer and in the receiving layer a color image as well as a reversal silver image.

It is to be noted that this process only yields one color images.

However the processes described may be used also in the production of multi-eolor images. For this purpose either two or more 0ne-co1or partimages obtained by the described process may be superimposed on a single support or a light-sensitive multi-layer material may be used comprising more than one light sensitive layer and/or more than one receiving layer. In such material pairs of co-acting layers composed of a light sen sitive layer and a reception layer may be isolated by a barrier layer able to check any unwanted diffusion of silver halide. A suitable barrier layer may be constituted by a reception layer in which the diffusing silver halide is fixed by reduction and is thus prevented from diffusing into an adjacent layer. 'The silver image formed in the barrier layer is removed during the further processing of the material.

, A preferred embodiment of the invention comprises exposing to light a photographic material containing at least two pairs of coacting layers located on the same side of their support,.each' pair consisting of a light-sensitive silver halide EXAMPLE 1 Manufacture of the photographic material Solution A:

Gelatine l per cent cc 100 Silver nitrate g l.

Solution B: I Y Gelatine 20 per cent i cc 200 Hydroquinone g 1 At a temperature of 35 C. the solutions are mixed, jellified, shredded and washed. The

Washed mixture is melted and used in the prep aration of the following solution:

Solution Cc.

Washed mixture 35' Water 60 Alcohol 5 Aqueous 20% solution of formaldehyde 0.5

This mixture is coated upona filrn, provided already with a subbing layer. The coating is thoroughly dried. A not hardened silver halide emulsion is coated upon this layer. The layer is dried.

Production of the image (a) Exposure,

(5) Development in a methol-hydroquinone developer,

(0) Washing, V

(d) Difiusion by treating two minutes in a color developer of the following composition:

Water cc 1000 Diethylbenzenediamine-l,4 g 0.7 Sodium sulphite (anhydrous) g 3.5 Sodium carbonate (anhydrous) g- 2.5 Sodium hydroxide g 0.7 Sodium thiosulphate g 3 Dibromo 2,4 alpha-naphthol (acetonic solution of 15 per cent) cc 6 (e) Removing the upper layer by warm water, (I) Dissolving the silver (by means of the Farmers reducer) washing and drying.

EXAMPLE 2 Manufacture of the photographic material An emulsion layer and a reception layer are successively coated on a photographic film support as described in Example 1. To the reception layer coating solution are added however 50 cos. of a 15 per cent acetonic solution of di bromo-2A-alpha-naphthol per 100 cos. of coating solution.

Production 09 the image The exposure, the development and the washing are effected as in Example 1. The diffusionis carried out by applying the following" developer for two minutes:

Water cc 700 Diethyl para-phenylenediamine g 0.7 Sodium sulphite (anhydrous) g. 3.5 Sodium carbonate (anhydrous) g 2.5 Sodium hydroxyde g 0.7

Sodium thiosulphate g 3 Methanol cc 300 After thorough washing, the silver is removed with Farmers reducer and the image is again Washed and dried.

EXAMPLE 3 Manufacture of the receiving material Solution A:

Aqueous 6% solution of gelatine cc 1000 Aqueous solution of sodium sulphide 1 per cent cc 8 Aqueous solution of stannous chloride 1 per cent cc 6 Sodium thiosulphate g 12 Solution B:

Water cc 40 Sodium carbonate g 2 4 hydroxy 5 methoxy benzylidenerhodanine g 1 V The two solutions are mixed. The mixture is coated upon a paper support and the layer formed is dried.

Production of the image A photographic material comprising a silver halide emulsion layer is exposed and together with the above described reception material is placed in a metol hydroquinone developing, solution. After development, the silver halide material and the receiving material ar squeezed together. After three minutes, the two materials. are separated. The reception material is freed from silver by means of Farmers reducer and; washed. In this way an orange-red image is left in the receiving material.-

EXAMPLE 4 Manufacture of the photographic material Production of the image (a) Exposure,

(1)) Development in a metal hydroquinone developing solution,

(0) Diffusion for 2 minutes in the following bath:

Water cc 1000 Sodium bisulphite g.... 30 Sodium hydrosulphite g 5 The dyestuff is bleached out at the points where silver was formed during the first development. After removal of the silver a positive dyestufi image is obtained.

I claim:

1. The photographic process of producing dyestuff images which comprises exposing to light a photographic material containing a light-sensitive silver halide emulsion layer, and then developing said material while said layer is in contact with a reception layer containing a binder and approximately 0.5 to 1.5 g. per g. of the binder of a substance accelerating reduction and forming nuclei and selected from the class consisting of colloidal silver, sulfides and substances containing a labile sulfur atom, in the presence of a color coupler which couples with the oxidation product of an aromatic amino developer with a developer containing an amino-aromatic developing agent and a thiosulfate silver halid solvent.

2. The photographic process of producing dyestufi images which comprises exposing to light a photographic material containing a light-sensitive silver halide emulsion layer, contacting said layer with a reception layer containing a binder and approximately 0.5 to 1.5 g. per 100 g. of the binder of a substance accelerating reduction and forming nuclei and selected from the class consisting of colloidal silver, sulfide and substances containing a labile sulfur atom, and developing said layer in the presence of a color coupler which couples with the oxidation product of an aromatic amino developer with a developer containing an amino-aromatic developing agent and a thiosulfate silver halide solvent.

3. The photographic process of producing dyestufi images which comprises exposing to light a photographic material containing a light-sensentive silver halide emulsion layer, contacting said layer with a reception layer containing a binder and approximately 0.5 to 1.5 g. per 100 g. of the binder of a substance accelerating reduction and forming nuclei and selected from the class consisting of colloidal silver, sulfides and substances containing a labile sulfur atom and a color coupler which couples with the oxidation product of an aromatic amino developer and developing said layer with a' developer containing an amino-aromatic developing agent and a thiosulfate silver halide solvent.

4. The photographic process of producing dyestufi images which comprises exposing to light a photographic material containing at least two layers arranged in superposition on one and the same side of a support, one layer being a lightsensitive silver halide emulsion layer, the other layer a reception layer containing a binder and approximately 0.5 to 1.5 g. per 100 g. of the binder of a substance accelerating reduction and forming nuclei and selected from the class consisting of colloidal silver, sulfides and substances containing a labile sulfur atom, and developing said material with a developer containing an aminoaromatic developing agent and a thiosulfate silver halide solvent, in the presence of a color coupler which couples with the oxidation product of an aromatic amino developer.

5. The process of claim 4, as applied to a photographic material in which the color coupler is References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 916,616 Schwartz Mar. 30, 1909 1,228,680 Kent June 5, 1917 1,499,230 Lage June 24, 1924 1,900,870 Seymour Mar. 7, 1933 1,905,438 Capstaff Apr. 25, 1933 1,939,231 Seymour Dec. 12, 1933 2,091,713 Marines et a1 Aug. 13, 1937' 2,179,234 Schneider Nov. 7, 1939 2,196,226 Murray et a1 Apr. 9, 1940 2,310,227 Gaspar Feb. 9, 1943 2,328,034 Sease et a1 Aug. 31, 1943 2,336,327 Weissberger et a1. Dec. 7, 1943 2,350,380 White June 6, 1944 2,352,014 Rott June 20, 1944 2,363,764 White Nov. 28, 1944 2,369,171 Murray Feb. 13, 1945 2,371,740 Dearing et a1 Mar. 10, 1945 2,543,181 Land Feb. 27, 1951 FOREIGN PATENTS Number Country Date 873,507 France Mar. 23, 1942 716,428 France Dec. 21, 1931 879,995 France Mar. 10, 1943 OTHER REFERENCES Sci. et Ind. Phot, 2nd series, vol. 13, July, August 1942, pages 151-152.

Ricketts, Positive Portraiture Direct, British Journal of Photography, June 5, 1914, page 446 cited.

Mees, The Theory of the Photographic Process (1942), published by The Macmillan Co.. New York (page 96) 

1. THE PHOTOGRAPHIC PROCESS OF PRODUCING DYESTUFF IMAGES WHICH COMPRISES EXPOSING TO LIGHT A PHOTOGRAPHIC MATERIAL CONTAINING A LIGHT-SENSITIVE SILVER HALIDE EMULSION LAYER, AND THEN DEVELOPING SAID MATERIAL WHILE SAID LAYER IS IN CONTACT WITH A RECEPTION LAYER CONTAINING A BINDER AND APPROXIMATELY 0.5 TO 1.5 G. PER 100 G. OF THE BINDER OF A SUBSTANCE ACCELERATING REDUCTION AND FORMING NUCLEI AND SELECTED FROM THE CLASS CONSISTING OF COLLOIDAL SILVER, SULFIDES AND SUBSTANCES CONTAINING A LABILE SURFUR ATOM, IN THE PRESENCE OF A COLOR COUPLER WHICH COUPLES WITH THE OXIDATION PRODUCT OF AN AROMATIC AMINO DEVELOPER WITH A DEVELOPER CONTAINING AN AMINO-AROMATIC DEVELOPING AGENT AND A THIOSULFATE SILVER HALIDE SOLVENT. 